In July my registration was up, and as a condition of renewing the registration, I had to run my 13 PI through emissions. Which meant I had to replace the catalytic convertor that had been throwing a P0430 off and on for the past year and a half.

I had a local shop replace the cat with an OEM part. The P0430 went away. However, 3 (Evap, O2 and O2 Heater) of the sensors required for running it through emissions did not set as ready. I took it into the emissions testing station, and failed the test but it allowed me to renew the registration and gave me two months to get the car to pass the emissions test. I was told some of the sensors can be stubborn, but they should become ready after a week or two of driving. Even if there was one that wasn't ready, that was ok.

After 7 weeks of driving (10k miles, and about 100 DTCs completed), the O2 and O2 Heater sensors are still not ready (The evap sensor did become Ready). If the car can't pass emissions by the weekend, the registration gets suspended until I can pass emissions. I have taken it into two garages in the last two week and they have no idea what is wrong as the O2 and O2 Heater normally set almost immediately, and it goes to a dealership tomorrow for computer and OBD diagnostics and firmware updates.

If you only replaced one of the catalytic converter, chances are the other one is bad. There are two total. Normally when I replaced the catalytic converters I replace the up and downstream O2 sensors. For the FPIS, the upstream O2's are the same length. However, the downstream ones are different lengths (but they are color coded and the length is obvious where they belong). If I remember right, the Ford part # have the downstream O2 sensors mixed up on which side they belonged.

You could buy new O2 sensors first and see if that will solve the problem, if not, chances are the 2nd catalytic converter was bad.

I didn't beat around the bush for getting my FPIS catalyic converters done. The parts needed along is about $1,000 for two cats (and gaskets + a few nuts) and four O2 sensors. Luckly, I found someone who was willing to put those cursive things in for $500.